The Concept of Computed Tomography - Essay Example

Introduction/Background Due to inadequate supply of oxygen and blood to the brain because of the blockage in the artery, an area of the brain tissue may die which is called cerebral infarction or ischemic stroke (Giraldo 2007). Computed Tomography (CT) was used until the later part of 1980s chiefly to eliminate hemorrhage in patients suffering with severe stroke. Although CT scan can help keep out hemorrhage and diagnose early symptoms of infarction, it cannot dependably confirm the irreversibly damaged brain tissue in the unfortunate event of acute stage of ischemic stroke (Tomandl et al 2003). It is very important for the treatment of the ischemic stroke that the scope of the damaged made to be defined. Diagnostic requirements for imaging the patients with ischemic stroke changed due to the result of research made by National Institute of Neurological Disorder and Stroke (NINDS). A new treatment for ischemic lesions of the (MCA) middle cerebral artery territory was introduced. It is called Thrombolysis. A metanalysis was published and it summarizes the entire outcome for which Thrombolytic agents were used to treat severe ischemia in three to six hours (Kobayashi et al 2007). The result was significant decrease in patients with negative outcome after the treatment. However there was also higher threat of hemorrhage and death in the first ten days of treatment. At the increase of the time interval between the beginning of the stroke and thrombolytic treatment, the threat of death and hemorrhage also increases. The determining factor of the success of thrombolytic therapy depends greatly on the earliest detection of the unfortunate event. The study shows that those patients that have been diagnosed as early as three hours from the onset have the greater positive outcome. Thus, the efficiency of the diagnostic imaging is of uttermost importance. It will ascertain the right patients for thrombolytic therapy so that severe complications could be avoided. For this reason the efficient diagnostic imaging should greatly help (a) leave out intracranial bleeding, (b) to determine which brain tissue is irreversibly affected and which is still has the good chance to recover, (c) and recognize stenosis or narrowing of the passage of the major extra and intracranial artery. On time restoration of blood flow to an organ or tissue may help prevent death of cell and reestablish normal function (Tomandl et al 2003). Aim The one aim of the neuroimaging in ischemic stroke is to ascertain the tissue at risk of infaction (Murphy et al 2008). The aim of this study is to establish the accuracy of MRI compared to CT scan in the diagnosis of ischemic stroke. Through the accuracy of this imaging technique the physicians can increase the possibility of good outcome of the treatment the affected area or tissue. Significance As it has been pointed out, early and accurate diagnosis plays a major in the success of the treatment of ischemic stroke. Efficient imaging of the affected brain tissue is very important. A recent study has shown that (MRI) magnetic resonance imaging can identify more accurately ischemic stroke than the (CT) computed tomography. The MRI is superior in its detection of ischemic stroke compared to CT. This study was conducted on January of 2007 by National Institute of Neurological Disorder and Stroke (NINDS), a division of National Institute of Health (NIH). These findings, according to the NIH are straightforwardly related to the “real world clinical practice”. The study was done with real patients found in emergency rooms on daily basis. According to Dr. Walter Koroshetz of NINDS research have shown that patients who have come within the three hours of the onset (this is the timeframe given to successfully attack blood clotting in the brain tissue) have been found to be with no signs of visible damage. This means that injury in the brain can be avoided by the victims of a stroke if the blocked blood vessel can be re-opened immediately by the treatment needed. A research has been conducted to establish and determine if MRI is better in diagnosing ischemic stroke than the CT scan. X-rays are passing through the different angles of the body and processing the cross-sectional images or slices of the internal structure of the organ or body with the CT scan. The MRI is using radio waves and powerful magnet produced by a computer to give complete slices of 3D images of body configurations and nerves. To increase the visibility of specific areas or tissues, a contrast dye is used in both of the imaging techniques. The results of the study was remarkable by which the MRI was found to be five times more sensitive and two times more accurate for detecting ischemic stroke (http://www.huliq.com/8348/mri-more-sensitive-than-ct-in-diagnosing-form-of-acute-stroke). Approach Patients who come in the hospital for the treatment of possible stroke are most likely to get different diagnosis. As physicians should be certain first of the diagnosis of the patient before giving any treatment, the physicians are most likely to rely on the efficiency of the imaging equipment. The research conducted by NINDS in 2007 has shown that MRI is two times more correct in detecting stroke from non-stroke. Because of this outcome, according to Steven Warach, M.D., Ph.D., the senior investigator of this research, MRI should be the ideal technique of imaging for detecting severe stroke. There has been also a study conducted by NINDS of which 217 patients out of 356 were diagnosed of acute stroke. It has been established that MRI had 83% sensitivity for the finding of any type of severe stroke compared to the 26% of CT (Vega 2007). The researchers found MRI to detect severe stroke or ischemic stroke, 46% of 356 patients compared to 9.8% of 356 patients. Also, MRI was equivalent to CT in identifying intracranial hemorrhage. It is also important to note that the researchers found in the first three hours of the onset of symptom MRI can detect ischemic stroke in 41(46%) of ninety patients compared to the CT which can only detect 6(7%) out of the 90 patients. It has a very significant proposition with the stroke victims who are qualified for thrombolytic therapy. Thus, if MRI is readily available, it would mean speedy analysis or diagnosis and increased chance of thrombolytic therapy within the three hours time frame it needs. Thus it would result in more positive outcome for the patients (Vega 2007). Description of personnel Because non-specialists are always involved in the imaging studies, and severe stroke are usually evaluated by them; the modality of imaging with greater sensitivity and greater intra-rater dependability must be used. With this pointed out, MRI is found to be more efficient in detecting acute ischemia. MRI should be the ideal test for correct analysis of patients suspected of severe stroke. Vega together with the editorial Dr. Donnan, MD, Dr. Dewy, MD, Dr. Davis, MD, of the University of Melbourne, in Australia stated that the outcome of this study calls for the immediate introduction of MRI as the equipment for standard diagnosis of stroke. This will ensure a greater understanding of the pathogenesis of stroke to direct treatment and the following management. However studies are continuing, in order to understand the complementary functions of both MRI and CT in the field of imaging (Vega, 2007). References Reference list: Brunser Alejandro M., MD; Lavados Pablo M., MD; Hoppe Arnold , MD; Lopez Javiera, MD; Valenzuela Marcela, MD; Rivas Rodrigo , MD.eds 2009 Stroke In-text: Brunser et al 2009 Reference list: Giraldo Elias, MD. 2007 Ischemic Stroke http://www.merck.com/mmhe/sec06/ch086/ch086c.html (Accessed October 18, 2009). In-text: Merck Manual Home Edition 2007 Reference list: harminka 2007. MRI more sensitive than CT in diagnosing form of acute stroke http://www.huliq.com/8348/mri-more-sensitive-than-ct-in-diagnosing-form-of-acute-stroke (Accessed October 18, 2009). In-text: Huliq News 2007 Reference list: Kobayashi Adam , MD, PhD; Wardlaw Joanna M., MBChB, MD, FRCR, FRCP, FMedSci; Lindley Richard I., MD, FRCP, FRACP; Lewis Steff C.,PhD, MSci; Sandercock Peter A.G., DM, FRCPE, FMedSci; Czlonkowska Anna, MD, PhD., eds. 2009 Stroke In-text: Kobayashi et al 2009 Reference list: Murphy Blake D., PhD, Fox Allan J.,MD, Lee Donald H., MD, BCh, Sahlas Demetrios J.,MD, Black Sandra E.,MD,. Hogan Matthew J.,MD, Coutts Shelagh B. ,MD, Demchuk Andrew M.,MD, Goyal Mayank ,MD, Aviv Richard I.,MD, Symons Sean ,MD, Gulka Irene B.,MD, Beletsky Vadim ,MD, Pelz David,MD, Chan Richard K.,MD, Lee Ting-Yim, PhD, eds. 2008 Radiology In-text: (Murphy et al 2008) Reference list: Tomandl Bernd, MD, Klotz Ernst , Dipl Phys., Handschu Rene , MD, Stemper Brigitte, MD, Reinhardt Frank, MD, Huk Walter J, MD, Eberhardt K.E., MD, Fateh-Moghadam, Suzanne MD, eds. 2003. RG. In-text: (Tomandl et al 2003) Reference list: Vega Charles, MD, FAAFP. 2008 MRI Superior to CT for Detection of Stroke http://cme.medscape.com/viewarticle/551515?rss (Accessed October 18, 2009). In-text: MedScapeCME 2008 Read More